Patient Population
We performed a single-center, retrospective observational study of
patients enrolled in a prospectively populated AF ablation database,
approved by the Johns Hopkins IRB and maintained continuously at Johns
Hopkins Hospital since 2002. Patients enrolled in the current
investigation underwent ablation for either PAF or persAF from January
2014 through March 2019. In that period, 307 patients were identified
who had received at least four weeks of continuous therapy with
amiodarone for rhythm-control purposes in the one-year window prior to
AF ablation. PAF patients were treated with Amiodarone at a minimum
maintenance dose of 200mg per day for at least four weeks; persAF
patients were treated with loading doses of amiodarone followed by
maintenance dosing, and underwent electrical cardioversion (CDV) to
restore NSR after at least two weeks of amiodarone therapy if necessary.
Patients were divided into two groups based on clinical response to
amiodarone. The amio-success group (n=183) maintained NSR for the
entirety of therapy with amiodarone and presented for PVI in NSR. The
amio-failure group (n=124) included patients who were loaded for with
amiodarone for a minimum of 4 weeks and cardioverted if necessary, but
who nevertheless experienced either recurrent episodes of PAF or persAF.
Patient characteristics were systematically recorded and included age,
gender, comorbidities, history of anti-arrhythmic use and cardioversion,
AF subtype (paroxysmal, persistent, or long standing persistent), and
baseline echocardiographic parameters (left atrial size and left
ventricular ejection fraction [LVEF]). Procedural data including
pre-procedural imaging, peri-procedural anticoagulation approach,
ablation information (RF v. cryoballoon; PVI only v. PVI with non-PV
targets; target power, force, and temperature parameters) were similarly
recorded.
Arrhythmia recurrence and peri-procedural complications were ascertained
based on monitoring strategies suggested in the consensus document
[1]. Arrhythmia recurrence was defined as any AF or atrial
tachyarrhythmia (AT) sustained for >30 s recorded by a
surface electrocardiogram or rhythm monitoring device after a 90-day
blanking period. Procedure-related complications, including vascular
complications, major bleeding, phrenic nerve palsy, cerebral embolism,
pericardial effusion/tamponade, atrioesophageal fistula, or extended
hospitalization (>48 h) were assessed. All patients were
observed in the hospital for a minimum of one-night post-ablation.
Routine follow-up (history, exam, and electrocardiography) was performed
at the outpatient clinic or by a local cardiologist at 3, 6, and 12
months, and additionally, if prompted by symptoms. Holter or event
monitors were arranged for patients in whom symptoms suggestive of AF
developed in the post-blanking follow-up period. Pacemaker interrogation
records were also used for arrhythmia recurrence monitoring when
available. AAD therapy, if present at the time of ablation, was
discontinued at the 3-month follow-up visit based on the operator’s
discretion. Reinitiation of AAD therapy post-blanking period was
considered a procedural failure. Outcomes were assessed via electronic
health records.